The inverted type liquid sealed mount like above is publicly known and comprises an insulator which forms a vibration isolating main body made of an elastic body such as rubber or the like and surrounds a part of a liquid chamber, the liquid chamber being partitioned upward and downward into a secondary liquid chamber on the upper side and a primary liquid chamber on the lower side, and a damping orifice connecting the secondary liquid chamber and the primary liquid chamber, wherein the insulator projects in the upward direction in substantially a chevron shape into the primary liquid chamber.
In the case of using it as an engine mount, an engine is mounted on an inner metal fitting which is integrally formed with the insulator, and an outer metal fitting surrounding the liquid chamber is mounted on a vehicle body. The engine is supported in a suspended condition, whereby the inverted type liquid sealed mount is also referred to as a suspended type mount.
An example of the inverted type liquid sealed mount as above is shown in FIG. 9 which is a cross sectional view corresponding to FIG. 3 of the present invention. FIG. 9(A) is a cross sectional view taken along a mount axis L of the inverted type liquid sealed mount (a cross section taken along line A-A of FIG. 9(B)), and FIG. 9(B) is a transverse cross sectional view (a cross section taken along line B-B of FIG. 9(A)). With respect to this inverted type liquid sealed mount, an inner metal fitting 102 to be mounted on the engine and an outer metal fitting 103 of cylindrical shape to be mounted on the vehicle body are connected by an insulator 108. An opening section of the outer metal fitting 103 is covered with a diaphragm 104. An inside of the liquid sealed amount is partitioned by a partition member 105 into a primary liquid chamber 106 and a secondary liquid chamber 107. A damping orifice 109 provides a connection between the primary liquid chamber 106 and the secondary liquid chamber 107.
The insulator 108 forms a main body section 110 a center portion of which projects upwardly in substantially a chevron shape. A circumference of the insulator 108 forms a foot section 112 which extends outwardly in the radial direction to reach and be united with the outer metal fitting 103. In a circumference of the main body section 110 there is formed an annular liquid chamber 106a of substantially a V-shaped cross section. This annular liquid chamber 106a is a part of the primary liquid chamber 106 and is configured to produce liquid resonance in a high frequency range above a resonance frequency of the damping orifice 109 when the liquid flows annularly within the annular liquid chamber 106a by a vibration in the direction orthogonal to the mount axis L (hereinafter, referred to as “horizontal vibration”). This liquid resonance shall be referred to as “annular liquid chamber resonance”.
Further, in the main body section 110 there are continuously and integrally formed flow resistance projections 120 and 130 which project upwardly and integrally from an outer lateral surface of the foot section 112 and which are of a cylindrical shape being open upwardly. As shown in FIG. 9(B), the flow resistance projections 120 and 130 are formed concentrically in a ring shape in a circumference of the main body section in such a way as to cause the flow resistance to the annular flow.